This invention relates to a process, specifically to a process for preparing [1H]-isoindolin-1-one-3-carboxylic acid, a compound potentially useful as an intermediate leading to a surrogate for the amino acids proline or phenylglycine.
The literature procedure for preparing [1H]-Isoindolin-1-one-3-carboxylic acid consists of three individual reaction steps starting with the oxidation of naphthalene to phthalonic acid, followed by formation of 1-hydroxyphthalazin-4-carboxylic acid and its subsequent reduction to [1H]-Isoindolin-1-one-3-carboxylic acid. The literature procedure, J. Prakt. Chem., 146, 307 (1936), provides the product of the present process invention in an overall yield of 9-11%.